Damper operating mechanism for



Oct. 1l, 1949. P. H. ROWE 2,484,745

DAMPER OPERATING MECHANISM FOR ELECTRIC PERCUSSION INSTRUMENTS FiledApril 50, 1947 3 Sheets-Sheet 1 Cet. l1, 1949; P. H. RowE 2,484,745

DAMPER OPERATING MECHANISM FOR ELECTRIC PERCUSSION INSTRUMENTS FiledApril 50, 1947 4 5 Sheets-Sheet 2 f 1 l l u nl l u x4 LMM 30 lllw'" /f/46/ 45 L MW// Z2 25 29 3a 44 I-g 4 IIL.. IW.

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Ary-ORME Oct. ll, 1949. P. H. RowE l DAMPER OPERATING MECHANISM FORELECTRIC PERCUSSION INSTRUMENTS Filed April 30, 1947 3 Sheets-Sheet 3Irl.

Patented Oct. 11, r`1949 DAIVIPER OPERATING MECHANISM FOR ELECTRICPERCUSSION INSTRUMENTS Paul H. Rowe, Los Angeles, Calif., assigner toMaas-Rowe Electromusic Corporation, Los Angeles, Calif., a corporationof California Application April 30, 1947, Serial No. 744,87.6

13 Claims.

This invention relates to an electrical percussion instrument of thetype in which vmetal bars are struck to produce musical tone byvibration of the rod.

Usually, the bars of varying lengths are suspended side by side` inclosely spaced relation. The suspension permits some freedom of motion,whereby they may freely vibrate. Ay striker is associated with each barandoperated by an electromagnet, or solenoid, and a plunger `of magneticmaterial. A common arrangement is one in which the strikers lare locatedbelowthe bars, a keyboard being provided for controlling thee1ectromagnet circuits.

A damper, usually of feltfmay be arranged for each bar, to stop thevibrations of the bar except when the striker associated with the bar isoperated. It is one kof the objects of this invention to improve, ingeneral, 'the manner in which the dampers are operated. e

It is another object kol." this'inventionto' make it possible to supportthe damper in 4a 'compact and simple manner on* the* correspondinglstriker'. For this purpose, a special form of supportjfor the damper isutilized, and which' is compact and of such small cross section that itmay readily pass between adjacentbars, so'thatthe' damper may rest onthe top ofthe bar-and therebyl suspend the plunger carrying the striker.

At times it may bedesirable to permit the bars to vibratesympathetically when one of the bars is struck. This entails thenecessity of raising all of the dampers from the bars. A-It risanotherobject of this inventionto'provide `a. simple mecha'- nism forraising therdampers, and especially by the aid ofelectromagnetsthatoperate Ito lift the plungers slightlywithout bringingthem into contact with the bars. i f

Preferably, this lifting action is controlled from thekeyboardbytheaid'ofv one or more electromagnets. -f It is-still another object/ofvthis invention to provide an arrangementof this character in which`only a small electric lpower is needed to lift all of the dampers. Thisisaccom` plished by aid of force-multiplyingk devices,` such as levers.It is stillanother-objectfof this invention to make it 4possible stillfurther to reduce the `power for this purpose bya'idofa specic leverarrangement. I 'v This invention possesses many Vothersadvantages, andhas other objects'which may be made more easily apparent fromKY aconsiderationof one embodiment of-the invention. For thisy pur# posethere is shown -aform linfther drawings accompanying and' forming partfr oil the ypresent 2 specification. This form will now be described indetail, illustrating the general principles of the invention; but it isto be understood that this detailed description is not to be taken in alimiting sense, since the scope of this invention is best defined by theappended claims.

Referring to the drawings:

Figure 1 is a side elevation of an electrical musical instrumentincorporating the invention;

Fig. 2 is a sectional view, taken along plane 2-2 of Fig. 1;

Fig. 3 is an enlargedfragmentary longitudinal, sectional View of theinstrument, the elements being shown in an alternative position;

Figs. 4 and 5 are sectional views, taken along planes 4--4 and 5-5respectively of Fig. 3;

Fig. 6 is a sectional view, taken along plane 6-6 of Fig. 4;

Fig. 7 is a sectional view, taken along plane 1--1 of Fig. 5; and

Fig. 8 is an enlarged sectional view, taken along plane 8-8 of Fig. 3.

The instrument includes a plurality of horizontally arranged resonantbars l. One of these 'bars is shown in Fig. 4. However, they are ofdifferent lengths and may include reduced portions, such as at 2, inorder to obtain the desired tone when the bar is struck by a striker ina manner to be hereinafter described.

These bars l are arranged in closely spaced relationship, as shownmostclearly in Fig. 1.

The support for these bars is provided by the aid of a wood framecomprising spaced upper and lower portions 3 and 4 (Fig. 1). The twosections of the frame 3 andr 4 are held apart by the end spacers 5, thebars l extending between these sections. Each of the frame sections,furthermore, has a central, rectangular opening extending substantiallythe entire length of the bar I from one side of the frame to the other.The bars I, furthermore, are suspended by the air of cords '6 from thetop frame 3. These cords are anchored to a series of anchors l in theform of screw eyes threaded into the top of the frame 3. Since thespecific manner of suspending the bars forms no part of the presentinvention, it is sufcient to state that these suspensions occur adjacentthe ends of the bars, by the aid of the cords, in a manner described andclaimed in a copending application, Ser. No. 744,875, led April 30,1947, in the name of Paul H. Rowe.

The frame structure 3-4-5 is mounted on a pair of wood cross-pieces 8 bythe aid of the interposed felt washers 9. These cross-pieces, in turn,are supported 'on a main base structure 3 including a base plate I andthe end pieces II and I2.

This mounting may be accomplished by the aid of a pair of screws I3 thatpass through the support 8 and include the rubber mountings I4.

Beneath the frame structure there are provided electromagneticallyoperated striker devices which are shown most clearly in Figs. 4 and 6.In order to provide a support for these devices, a pair oflongitudinally extending wood members or strips i5 and I5 are anchoredat their ends in the supports 8, as shown most clearly in Fig. 2.

In turn, as shown most clearly in Fig. 4, these wood members support ahollow metal frame ITI beneath their lower edges. A wood strip I8 .canbe provided on one side of the frame toserve asra support for variouselectrical terminals` not shown.

The frame I'I extends from one end to the other of the instrument.Within the frame are supported the electromagnet coils I9, having axestransverse to the bars I. There are two rows of these coils in staggeredrelation. These coils provide electromagnetic power for operating thestriker devices 2i) (Figs. 4 and 6).

In order that these Strikers may be guided in a vertical direction, thetop and bottom of frame I'I have a plurality of apertures 2Irespectively coaxial with the axes of the coils I9. In theseaperturesare located insulation sleeves 22 which serve as guides for the strikermechanisms. These sleeves extend completely through the frame.

When a specific coil I9 is energized, it will serve to draw in a hollowmagnetic core 23 that is `guided in the sleeve 2U. Accordingly, when acorresponding coil I9 is energized, the core 23 is violently pulledupwardly and carries the striker mechanism upwardly to hit the bar I.

Each striker mechanism includes-a rectangular wood strip 24 (Fig. 6)that is anchored at its lower end in the core 23. At its upper end, itcarries a felt cover 24 that comes into contact with the bar I when thecorresponding electromagnet is en- 'ergized In the unenergized positionyindicated in Fig. l, the tops of strips 24 are spaced a considerabledistance below the corresponding bar I.

Each of the striker mechanisms is suspended freely within the sleeve 22by the aid of a damper 25 wliich'engages the upper sde'of the bar I. Thedamper 25 (Figs. 3, 4, and 6) may be formed Zby a pair of felt membersbetween which is accommodated one leg 26 of a damper supporting rod 2l.This damper supporting rod is made from relatively thin wire, and canreadily pass between adjacent bars I. Its lower end 23 extends`horizontally and enters transversely into the striker ZI). Preferably,this end 28 may be knurled to form a tight iit.

The core 23 of each of the mechanisms .forms a plunger for thecorresponding solenoid coil I9. In playing the instrument, the core isultimately centralized within the coil I9. Each energization carries thestriker mechanism upwardly, and a single blow is imparted to the bar I,after which I the plunger falls back to central position; and when thecoil is deenergized, the striker mechanism falls to the lowered positionillustrated in Fig. l. The damper pad 25, while the corresponding coilI9 is energized, is free of bar I, and permits the bar I to have a freevibration until the plunger returns to its lowermost position.

At times it is required that all of the dampers 25 for all of the bars Ibe released from the :bars

in order to cause the bars to sustain a sympathetic vibration. This isaccomplished in the .present instance by the aid of a wood platform 29(Figs. 1, 3, and 4) Which extends underneath all the cores 23 andlengthwise of the instrument. Preferably, a felt pad 30 is disposedabove the platform. This platform 2.9 is shown in the inactive positionof Fig. 1. It is, however, shown in raised position in Figs. 3 and 4.The raised position of the plunger is illustrated in Fig. 6. In thisposition all of the damper pads 25 have been lifted away from the barsI.

The ends of the platform 29, as shown most 'clearly inFig. `3, are:received in slots 3I formed vertically in the :central portion of thesupports Id land I2.

The mechanism for optionally raising the plat- 'form "to a sufficientdistance to release all of the pads without striking the bars I will nowbe described.

On one side of the instrument, and supported on thesupporting member I5,are a pair of levers 32 and 33. Corresponding levers 34 and 35 aresimilarly supported on the supporting member I6.

These levers are Veach mounted for pivotal movement on the supports I5.and 'I 6, as indicated most clearly in Fig. 4. Thus, passing throughand forming a .pivot ,for .the right-hand end of lever 32 there is awood screw .36. This wood screw passes .throughabushng 31 accommodatedbetween the washers 3B and .39. On the bushing 31 `is .pivoted thelever32.

Each of the levers 32, 33, 34, .andv35 is connected, as by .a link 49,to the platform 29. Accordingly, when levers n32 .and 33 are raised,.the links serve to raise the .platform 29. Since there are four .suchlinks arranged symmetrically, the platform is lifted evenly tocontactall of the cores 23 substantially simultaneously.

The link 40 is hooked .at .its upper end over a screw 4I (Eig. 3).carried by the lever. As its lowerend,as shownin Fig. .8, it passesthrough a screw-,eye 42 that -is attached to the platform 29. Thisscrew-eye may be lined with .a felt washer 43. Furthermore, the link 4.0.has an adjustable stop 44 beneath 4the eye 42. y This stop is held inany adustedposition by the ,aid ofthe set screw 45 which extends`transversely.of the link 40, and 1which `passes into the member 44. Afelt pad or washer 46 .is interposed between .the stop 44 and the-eye42.

Accordingly, :by proper adjustmentof the position of all lof the .stops44, movement of the four levers 32-35 can bemadesuch as to elevate theplatform `to the positionof Fig. 3.

Operation of .allof the levers `is accomplished by the aid of solenoids,one for each lever. The solenoidstructure for llever132 will bedescribed, and it 'will be Vunderstood that similar solenoid structuresare lemployed rior `the remaining levers.

Thus, as .shownmost clearlyin Figs. 3 and 5, a coil -4'I .is supportedin the frame II, and carries a core-48 of the same-:generalfcharacter asvcores 23. InfFig. 5,.-the-core `48..:lsshown in the position that it`assumes zwhen -thecoil 41 is energized.

The hollow core 48 .carries a wood strip 49 (Figs. 5.and 7)..This'wood-strip is connected to the lever 32 by the aid of-a fstiff-Wire 50, which passes through -a :large .clearance aperture 5I in .thesupporting -strip 1li. .In lorder *to render the operation :on theflever .-nolseless, felt sleeves 52 and 53 Aaredisposed-On the Wire 50.The upper edge -of-the apertureil .serves vas a limit vfor the vupwardmovementof thelever 82.

fase-m45 In order that small solenoidcoils 41,.uslng only limited power,may be provided to lift the platform 2.9 and all of the cores 23;, useis madeof an auxiliary spring force associatedr with lever 32 and lever34. Thus, a tension spring 54 is anchored at its left-hand end toy ascrew-eye 55 attached adjacent the free end of thelever 32. Its otherend is anchored to a Wire 56 that passes through stationary guides 5lmounted. on the support I5, and that has an adjustable stop 58.

In the position of Fig. 1, in which the platform 29 is in the inactiveposition, the direction of the force exerted by the spring is such thatthis force passes quite close to the pivot of the lever 32. Accordingly,in this position the torque tending to turn the lever 32 in a Aclockwisedirection, due to the spring tension, is very small and not suiiicientto raise the platform and its associated parts. The weight of theseparts is sufficient, when the coils 4l are de-energized, to carry theplatform 29 to its l'owermost position.

However, just as soon as the .plungers 48 are elevated slightly, thetorque arm of the spring force increases rapidly. Accordingly, thespring tension helps materially to raise 'the platform.

The inventor claims:

1. In an electric percussion instrument: a suspended horizontal resonantbar; a striker below the bar; a damper 'resting on the bar and above it;a connection between the damper and the striker; and electromagneticmeans for operating said striker, including a core suspended by thedamper.

2. In an electric percussionifnstrument: aphirality of spaced parallelresonant bars; a plurality of strikers respectively for the bars andmovable transverse to the axis of the bars; a damper for each barlocated 'on the opposite side of the bar from the striker; a connectionbetween each striker and the corresponding damper and passing betweenadjacent bars; and electromagnetic means for operating each strikerincluding a core for each striker suspended by the respective damper.

3. In an electric percussion instrument: a plurality of horizontallyarranged, parallel spaced resonant bars; a plurality of strikersrespectively for the bars and disposed to move upwardly against thebars; electromagnets having plungers connected to the strikers; a damperfor each bar and disposed above the bars; and a connection between thedamper and striker of each bar, and passing between adjacent bars; thedamper thereby serving to suspend the associated striker and plungerfrom the bar.

fl. In an electric percussion instrument: a plurality of spaced parallelresonant bars; a plurality of strikers respectively for the bars andmovable transverse to the axis of the bars; a damper for each barlocated on the opposite side of the bar from the striker; a connectionbetween each striker and the corresponding damper and passing betweenadjacent bars; and means for simultaneously moving a plurality of thestrikers but not into contact with the bars, for moving thecorresponding dampers off the bars.

5. In an electric percussion instrument: a plurality of horizontallyarranged, parallel spaced resonant bars; a plurality of strikersrespectively for the bars and disposed to move upwardly against thebars; electromagnets having plungers connected to the strikers; a damperfor each bar and disposed above the bars; a connection between thedamper and striker of each bar,

:and passing between adjacent bars; the. damper vthereby serving tosuspend the associatedy striker and plunger from the bar; and means forsimultaneously lifting a plurality 'of the plungers to release thedampers, said movement being insufficient to move the strikers intocontact with the bars.

6. In an electric percussion instrument: aplurality of horizontallyarranged, parallel spaced resonant bars; a plurality of strikersrespectively for theV bars and disposed to move upwardly against thebars; electromagnets having plungers connected to the strikers; a damperfor each bar and disposed above the bars; a connection between thedamper and striker of each bar, and passing between adjacent bars; thedamper thereby serving to suspend the associated striker and plungerfrom the bar; a vertically movable member beneath the plungers; andmeans for moving said member to lift a plurality of plungers forreleasing the dampers, said movement being insuicient to move thestrikers into contact with the bars.

7. In an electric percussion instrument: a plurality of horizontallyarranged, parallel spaced resonant bars; a plurality of strikersrespectively for the bars and disposed to move upwardly against thebars; electromagnets having plungers connected to the strikers; a damperfor each bar and disposed above the bars; a connection between thedamper and striker of each bar, and passing between adjacent bars.; thedamper thereby serving to suspend the associated striker and plungerfrom the bar; a platform normally spaced below the plungers; and meansfor moving the platform to engage the lower ends of the plungers and torelease the dampers `from the bars.

8. In an electric percussion instrument: va plurality of horizontallyarranged. parallel spaced resonant bars; a plurality of strikersrespectively for the bars and disposed to move upwardly against thebars; electromagnets having plungers connected to the strikers; a damperfor each bar and disposed above the bars; a connection between thedamper and striker of each bar, and passing between adjacent bars; thedamper thereby serving to suspend the associated striker and plungerfrom the bar; a common means for engaging the lower ends of theplungers; and means for raising said common means, comprising a lever; alink between the lever and said common means; and an electromagnethaving a plunger connected to the lever.

9.' In an electric percussion instrument: a plurality of horizontallyarranged, parallel spaced resonant bars; a plurality of strikersrespectively for the bars and disposed to move upwardly against thebars; electromagnets having plungers connected to the strikers; a damperfor each bar and disposed above the bars; a connection between thedamper and striker of each bar, and passing between adjacent bars; thedamper thereby serving to suspend the associated striker and plungerfrom the bar; a common means for engaging the lower ends of theplungers; and means for raising said common means, comprising a lever; alink between the lever and said common means; an electromagnet having aplunger connected to the lever; and a spring connection urging the leverin a lifting direction, the direction of the force of the spring beingquite close to the axis of the lever when the lever is in inactiveposition, whereby the weight imposed on the lever when the electromagnet`7 'operating the lever is deenergized, is suicient to 'causereengagement of the dampers with the bars.

' 10. In an electric percussion instrument: a plurality of horizontallyarranged, parallel spaced resonant bars; a plurality of strikersrespectively for the bars and disposed to move upwardly against thebars; electromagnets having plungers 'connected to the strikers; adamper for each bar and disposed above the bars; a connection betweenthe damper and striker of each bar, and passing vbetween adjacent bars;the damper thereby serving to suspend the associated striker and plungerfrom the bar; a member beneath the plungers and normally out of contacttherewith; a plurality of levers connected to the member to raise it andthereby release the dempers; and electromagnets respectively connectedto the levers for operating them.

11. In an electric percussion instrument: a plurality of horizontallyarranged, parallel spaced resonant bars; a plurality of strikersrespectively for the bars and disposed to move upwardly against thebars; eleotromagnets having plungers connected to the strikers; a damperfor each bar and disposed above the bars; a connection between thedamper and striker of each bar, and passing between adjacent bars; thedamper thereby` serving to suspend the associated striker and plungerfrom the bar; a member beneath the plungers and normally out of contacttherewith; a plurality of levers connected to the member to raise it andthereby release the dampers; said levers being angularly movable onspaced parallel axes; electromagnets respectively connected to thelevers for operating them; and a spring connection between one lever anda stationary point for assisting the electromagnet, the direction of thespring force being close to the aXis of the respective lever, andincreasing as the lever operates; the weight of the member and its as- 8sociated parts being sufficient when the lever operating electromagnetsare deenergized, to return the member to inactive position.

12. In anelectric percussion instrument: a plurality of spaced resonantelements; a plurality of'strikers respectively for each element; adamper for each element; `a connection between the damperand the strikerof each element; independently operable means for operating the strikersso as to strike the elements; and means for simultaneously moving thestrikers toward the elements but short of contact of the strikers withthe elements, and thereby moving the dampers out of contact with theirrespective elements.

13. In an electric percussion instrument: a plurality oi spaced resonantelements; a plurality of strikers respectively for each element; adamper for each element; electromagnetic means for operating each ofsaid strikers, and including a core to which the respective striker isattached; a damper foreach element carried by the striker for theelement, said damper serving to suspend the core; and means forsimultaneously moving said cores for releasing the dampers, themovementor the cores being insufficient to cause contact between thestrikers and the elements.

PAUL H. ROWE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

